/* util.c */
struct file *file_lookup(const char *name);
-int file_write_dep(const char *name);
void *xmalloc(size_t size);
void *xcalloc(size_t nmemb, size_t size);
void *xrealloc(void *p, size_t size);
struct symbol *sym_check_deps(struct symbol *sym);
struct property *prop_alloc(enum prop_type type, struct symbol *sym);
struct symbol *prop_get_symbol(struct property *prop);
-struct property *sym_get_env_prop(struct symbol *sym);
static inline tristate sym_get_tristate_value(struct symbol *sym)
{